The short answer
A curtain wall is a continuous glass skin, so every drop is glass from top to bottom and the whole facade is on display. A punched window facade is a solid wall of masonry, precast or panels with individual window openings, so there is less glass but more stops, more frames and sills, and more runoff from the wall onto the glass.
What changes on a curtain wall
- Continuous drops. Crews work long, uninterrupted runs of glass, top to bottom.
- Every pane is visible. Streaks and missed panes show across the whole facade, so consistency matters more than anywhere else.
- Mullions and frames run the full height and collect dirt that washes onto the glass below.
- Glass count drives the job. More glass means more labor per drop.
What changes on a punched window facade
- Start and stop. Crews move between individual openings, with wall between them.
- Frames and sills make up more of the work relative to glass area.
- Recessed openings can sit back from the wall face, which affects how a pole or line reaches the glass.
- Runoff staining. Rain washing over precast concrete and masonry carries minerals onto the glass below. Left alone, those deposits bond and etch.
Side by side
| Curtain wall | Punched windows | |
|---|---|---|
| Glass area | The whole facade | Individual openings |
| Work pattern | Long continuous drops | Stop and start between openings |
| Frames and sills | Full-height mullions | A frame and sill at every opening |
| Staining risk | Dirt from mullions and frames | Mineral runoff from precast and masonry |
| What drives cost | Glass count and access | Number of openings, frames and access |
Mixed facades
Many buildings combine both: a curtain wall lobby and podium under a punched-window tower, or glass on one elevation and masonry on another. A good scope treats each elevation separately, with its own access method and glass count. See what a commercial window cleaning scope of work must specify.
What it means for your bids
Pricing follows the real labor: height and access, glass count and sides, glass condition and frequency. If two bids describe your facade differently, they are pricing different jobs. See why window cleaning bids vary so widely.
S&K scopes every elevation on the walkthrough and delivers a clear, fixed proposal. Start with the pricing calculator.
